Inspecting apparatus and inspecting method for circuit board

ABSTRACT

The present invention provides an apparatus and method for inspecting a circuit board at a high speed. An LCD driver module  100  as an object to be inspected has an onboard LCD driving LSI  110.  One circuit-wiring group  111  is connected to SEG terminals, and another circuit-wiring group  112  is connected to COM terminals of the LSI  110.  An inspection apparatus  1  generates an LSI drive signal and sends it to input terminals  113  of the LSI  110.  A pair of sensors  2, 3  are positioned opposedly to the circuit-wiring groups  111, 112,  respectively, in a non-contact manner. Each of the sensors  2, 3  detects voltage changes in the corresponding circuit-wiring group  111, 112  caused by driving the LSI  110,  and the detected signals are analyzed by the inspection apparatus  1.

TECHNICAL FIELD

The present invention relates to an apparatus and a method forinspecting a circuit board.

BACKGROUND ART

In manufacturing processes of a circuit board, after forming circuitwirings on a board, it is required to inspect the presence of adisconnection or open circuit in the circuit wirings.

Heretofore, an open circuit state in circuit wirings on a circuit boardhas been determined by bringing a pair of pins into contact with twodifferent portions of each circuit wiring and then checking conductionbetween the positions.

However, in an area of the circuit board, such as the vicinity of anintegrated circuit, where the circuit wirings are formed in closeproximity to each other, it is difficult to assure a sufficient intervalbetween the pins. On the other hand, a non-contact type inspectionmethod (Japanese Patent Laid-Open Publication No. 09-264919) has beenproposed. However, since this inspection method has still been requiredto bring one pin into contact with each input section of the circuitwirings, it has been suffered from complicated and time-consumingpositioning operations when circuit wirings such as those around anintegrated circuit are in close proximity to each other and each of thecircuit wirings has a short length.

In view of the problems in the above conventional methods, it istherefore an object of the present invention to provide an apparatus anda method capable of inspecting a circuit board at a high speed.

DISCLOSURE OF THE INVENTION

In order to achieve the above object, according to a first aspect of thepresent invention, there is provided an apparatus for inspecting acircuit board incorporating an integrated circuit, comprising: drivemeans for forcibly driving the integrated circuit to generate outputsignals sequentially from a plurality of output terminals of theintegrated circuit; detect means for detecting in a non-contact manner avoltage change in a plurality of circuit wirings connected to the outputterminal; comparison means for comparing the magnitude of the detectedvoltage change to a given value; and defect determination means fordetermining a defect in the circuit wirings according to the comparisonresult in the comparison means.

In the first aspect of the present invention, the detect means may beadapted to generate a waveform representing the voltage change, and whenthe waveform includes an abnormal waveform, the defect determinationmeans may be operable to identify defective one or ones of the pluralityof circuit wirings according to the location of the abnormal waveform ona time axis.

The detect means may include a sensor board opposed to the plurality ofcircuit wirings in a non-contact manner to detect the voltage change anyone part of the plurality of circuit wiring. Further, the sensor boardmay include a single metal plate which has a dimension arranged to coverthe plurality of circuit wirings and includes a single output terminal.

The plurality of circuit wirings may be driven to sequentially generatepulse signals as the output signals. In this case, the detect means maybe operable to sequentially differentiate the pulse signals and add thedifferential values to present the sum as a single output waveformrepresenting the voltage change.

The determination means may be operable, responsive to the comparisonresult in the comparison means indicating that the magnitude of thevoltage change is equal to or less than the given value, to determinethat the circuit wiring corresponding to the voltage change includes adisconnection.

According to a second aspect of the present invention, there is providedan apparatus for inspecting a circuit board for use in an LCD driver,comprising: detect means for detecting in a non-contact manner a voltagechange in all of circuit wirings connected in a one-on-one arrangementto terminals of an LSI for use in an LCD driver; determination means fordetermining whether or not the magnitude of the detected voltage changeis normal or abnormal; and identification means responsive to thedetermination of an abnormality in the voltage change to identifydefective one or ones of the circuit wirings according to the timing ofoccurrence of said abnormal voltage change.

In the second aspect of the present invention, the apparatus may furtherinclude drive means for forcibly driving the LSI to generate outputsignals sequentially from the terminals of the LSI.

The terminals may be segment terminals. In this case, the determinationmeans may be operable responsive to the voltage change less than a givenvalue to determine that the circuit wiring corresponding to the voltagechange includes a disconnection.

Alternatively, the terminals may be common terminals. In this case, thedetermination means may be operable responsive to the voltage changegreater than a given value to determine that the circuit wiringcorresponding to the voltage change includes a disconnection.

The determination means may be operable responsive to the voltage changegreater than a given value to determine that the circuit wiringcorresponding to the voltage change includes a short-circuit.

The timing of occurrence of said abnormal voltage change may be definedby a location on a time axis between adjacent timings of frame inversiondetected as periodical major voltage changes in the detect means.

In order to achieve the above object, according to a third aspect of thepresent invention, there is provided a method for inspecting a circuitboard incorporating an integrated circuit, comprising the steps of:forcibly driving the integrated circuit to generate output signalssequentially from a plurality of output terminals of the integratedcircuit; detecting in a non-contact manner a voltage change in aplurality of circuit wirings connected to the output terminal; comparingthe magnitude of the detected voltage change to a given value; anddetermining a defect in the circuit wirings according to the comparisonresult in the comparing step.

In the third aspect of the present invention, the detecting step mayinclude the step of generating a waveform representing the voltagechange, and the defect determination step may include the step of whenthe waveform includes an abnormal waveform, identifying defective one orones of the plurality of circuit wirings according to the location ofthe abnormal waveform on a time axis.

The detection step may include the step of positioning a sensor boardopposedly to the plurality of circuit wirings in a non-contact manner todetect the voltage change in any one part of the plurality of circuitwiring. In this case, the sensor board may include a single metal platehaving a dimension arranged to cover the plurality of circuit wirings,the metal plate including a single output terminal.

The driving step may include the step of forcibly driving the pluralityof circuit wirings to sequentially generate pulse signals as the outputsignals, and the detecting step may include the step of sequentiallydifferentiate the pulse signals and add the adjacent differential valuesto present the sum as a single output waveform representing the voltagechange.

The determining step may include the step of responsive to thecomparison result in the comparing step indicating that the magnitude ofthe voltage change is equal to or less than the given value, determiningthat the circuit wiring corresponding to the voltage change includes adisconnection.

According to a fourth aspect of the present invention, there is provideda method for inspecting a circuit board for use in an LCD driver,comprising the steps of: incorporating in the circuit board an LSI foruse in an LCD driver; forcibly driving the LSI to generate outputsignals sequentially from all of circuit wirings connected in aone-on-one arrangement to terminals of the LSI; detecting a voltagechange in the circuit wirings in a non-contact manner; determining ifthe magnitude of the detected voltage change is normal; and responsiveto the determination of an abnormality in the voltage change,identifying defective one or ones of the circuit wirings according tothe timing of occurrence of said abnormal voltage change.

In the fourth aspect of the present invention, the terminals may besegment terminals. In this case, the determining step may include thestep of responsive to the voltage change less than a given value,determining that the circuit wiring corresponding to the voltage changeincludes a disconnection.

Alternatively, the terminals may be common terminals. In this case, thedetermining step may include the step of responsive to the voltagechange greater than a given value, determining that the circuit wiringcorresponding to the voltage change includes a disconnection.

The determining step may include the step of responsive to the voltagechange greater than a given value, determining that the circuit wiringcorresponding to the voltage change includes a short-circuit.

The timing of occurrence of said abnormal voltage change is defined by alocation on a time axis between adjacent timings of frame inversiondetected as periodical major voltage changes in the detecting step.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing the entire construction of aninspection system according to one embodiment of the present invention;

FIG. 2 illustrates an equivalent circuit of a sensor, LSI and circuitwirings in the inspection system according to the embodiment of thepresent invention;

FIG. 3 is a block diagram mainly showing the internal construction ofthe inspection apparatus of the inspection system according to theembodiment of the present invention;

FIG. 4 is an explanatory diagram of a method for inspecting a circuitboard on the side of SEG terminals by use of the inspection apparatusaccording to the embodiment of the present invention;

FIG. 5 is an explanatory diagram of a method for inspecting the circuitboard on the side of COM terminals by use of the inspection apparatusaccording to the embodiment of the present invention;

FIG. 6 is a flow chart of the inspection method according to theembodiment of the present invention;

FIG. 7 illustrates an actual waveform detected by the inspection systemaccording to the embodiment of the present invention; and

FIG. 8 illustrates an actual waveform detected by the inspection systemaccording to the embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to the drawings, the present invention will now bedescribed in detail in conjunction with a preferred embodiment intendedsimply to show as an example. Therefore, the present invention is notlimited to any arrangement, numerical values and others of elements orcomponents described in this embodiment unless otherwise specified.

(Embodiment)

As one embodiment of the present invention, a system for inspecting acircuit board incorporating an integrated circuit will be describedbelow.

<Construction of Inspection System>

FIG. 1 is schematic diagram showing the inspection system in aninspection operation of a circuit board 100.

A liquid crystal display (LCD) driver module 100 as an object to beinspection has an onboard LCD driving LSI 110. A plurality of firstcircuit wirings 111 (hereinafter referred to as “SEG circuit-wiringgroup”) printed on the circuit board are connected to a plurality ofsegment (SEG) terminals of the LSI 110, respectively. A plurality ofsecond circuit wirings 112 (hereinafter referred to as “COMcircuit-wiring group”) are connected to a plurality of common (COM)terminals of the LSI 110, respectively. Further, a plurality of thirdcircuit wirings 113 are connected to a plurality of input terminals ofthe LSI 110, respectively.

The inspection system comprises an inspection apparatus 1 composed of acomputer, an SEG sensor 2, and a COM sensor 3. The inspection apparatus1 is a general-purpose computer incorporating an LCD driving program, acircuit and program for analyzing a detected signal from each of thesensors, an interface for allowing communication between the sensors andthe LCD driver module, and others.

The inspection apparatus 1 generates an LSI drive signal and sends it tothe input terminals 113 of the LSI 110. Voltage changes in each of theSEG and COM circuit-wiring groups 111 and 112 caused by the LSI drivesignal are detected by the sensors 2, 3, and then the signals detectedby the sensors 2, 3 are analyzed in the inspection apparatus 1.

The sensors 2, 3 are positioned opposedly to the SEG and COMcircuit-wiring groups 111, 112, respectively, in a non-contact manner.The sensors 2, 3 detect the voltage changes in the SEG and COMcircuit-wiring groups 111, 112 caused by driving the LSI 110, and sendsthem to the inspection apparatus 1 as detected signals. While thedistance between each of the sensors and the correspondingcircuit-wiring group is desired to be 0.05 mm or less, the voltagechanges can be detected as long as the distance is set in 0.5 mm orless. The sensors may be closely placed on the circuit board withinterposing a dielectric insulating material therebetween.

FIG. 2 shows an equivalent circuit showing the relationship of one ofthe sensors, the LSI and the corresponding circuit-wiring group. Asillustrated, it can be assumed that the sensor is connected with the LSIthrough a plurality of capacitive couplings. Thus, pulse waves from theLSI are converted into differential waves on a side of the sensor, andthen these differential waves are received by the sensor as a detectedsignal.

With reference to FIG. 3, the internal construction of the inspectionapparatus 1 will be described below. FIG. 3 is a block diagram showingthe hardware of the inspection apparatus 1.

The reference numeral 210 indicates a power supply for supplying a powerto the entire inspection apparatus 1, the reference numeral 211indicating a CPU for performing various operations and controlling theentire inspection apparatus 1, and the reference numeral 212 indicatinga ROM for storing programs executed in the CPU 211, fixed values or thelike, the reference numeral 213 indicating a RAM as a temporary memory.The RAM includes a program loading area for storing loaded programs, amemory area for digital signals received from the sensors, and others.

The reference numeral 214 indicates a hard disk (HD) as an externalmemory. The reference numeral 215 indicates a CD-ROM drive as a readdevice for a detachable storage medium.

The reference numeral 216 indicates an input/output interface. Theinspection apparatus sends and receives signals to/from a keyboard 218as an input device, a mouse 219 and a monitor 220 through theinput/output interface 216.

A jig 221 sends signals to the LCD driver module as a work, and switchesthe SEG sensor and the COM sensor. The computer as the inspectionapparatus 1 is expanded to have compatibility for inspecting the LCDdriver module, and an interface card 222 and an A/D conversion board 223are incorporated therein. The interface card 222 contains an amplifier222 a. Thus, the detected signal from each of the sensors is amplifiedby the amplifier, and then sent to the A/D conversion board 223. Theinterface card 222 further includes a power supply 222 b for jigcontrols. This is a booster operable to vary its supply voltage when thework includes a short circuit.

Various programs such as an LCD-driver control program, jig controlprogram and detected signal analysis program are stored in the HD 214,and each program is loaded on the program loading area of the RAM 213and executed. An image data (CAD data) representing each shape ofcircuit wirings in design is also stored in the HD 214.

The LCD and/or jig control programs may be installed by reading a CD-ROMwith the CD-ROM drive. Otherwise, these programs may be read from othermedium such as a FD or DVD, or may be downloaded via networks.

Each of the sensors 2, 3 is made of a conductive material includingmetals such as aluminum or copper, and semiconductors. Preferably, eachof the sensors 2, 3 has a dimension capable of covering all of thecircuit wirings or the circuit-wiring groups.

While FIG. 3 shows one mode in which the single inspection apparatus 1is connected to the single jig to inspect the single work, a pluralityof interface cards may be incorporated in a single inspection apparatusto simultaneously inspect a plurality of works.

With reference to FIG. 4, a method for detecting defects in the SEGcircuit-wiring group will be described below.

The LSI is forcedly driven so that its 1st to N-th terminals provideoutput pulse signals as shown in FIG. 4(a). Each point designated by thearrows X and Y is the timing for switching frames, and each of theoutput waveforms from the terminals is reversed.

The pulse signals as shown in FIG. 4(a) are detected by the sensor 2,and differentiated and added. The resulting sum forms a waveform as adetected signal having a shape as shown in FIG. 4(b). As illustrated, atthe timings X, Y for switching frames, each voltage in all of theterminals raises or turns down simultaneously to generate a relativelyhigh peak periodically. One frame period of time can be determined bydetecting these adjacent frame-switching points and counting the lapsedtime between the two points. As shown in FIG. 4(c), by checking theoutput signal of the sensor around a value n L/N derived from dividingthe frame time L by the number of the terminals N and multiplying theresulting quotient by a positive integer n, where n is equal to or lessthan the number of the terminals N.

For example, in FIG. 4, despite of existence of an output pulse signalfrom the 3rd terminal as shown in FIG. 4(a), no deferential waveform isdetected in the sensor output or detected signal as shown in FIG. 4(b).Thus, it can be determined that the circuit wiring connected to the 3rdterminal includes a disconnection, and thereby no voltage change iscaused at the corresponding position of the sensor. Further, if somecircuit wirings include a short circuit therebetween, voltage in thebooster circuit is varied by driving the terminal connected to thiscircuit wiring, and then voltage changes are caused in all of theterminals. This leads to a significant disorder in the sensor outputwaveform. FIG. 4(b) shows that the two circuit wirings connected to theN-1-th and N-2-th terminals are short-circuited mutually.

With reference to FIG. 5, a method for detecting defects in the COMcircuit-wiring group will be described below.

Differently from the SEG terminals, the COM terminals are turned on andoff in a sequential order during a regular LCD drive. Thus, the COMterminals are driven in the ordinary way without any additionalparticular control. However, by the ordinary way, the timing of turn-offin one of the terminals is simultaneous with the timing of turn-on inadjacent one, as shown in FIG. 5(a). Thus, if no defect, at any one ofthe timing, the differential value representing a voltage change in oneof the circuit wirings has the same magnitude as but the reverse sign tothat in adjacent one. That is, in a normal state free from any defect,the sensor output waveform formed by adding respective differentialvalues of all of the terminals will have a flat shape. As shown in FIG.5(b), only if one circuit wiring in the circuit group includes adisconnection, two circuit wirings connected to the terminals on bothsides of the terminal of the circuit wiring including the disconnectionhave turn-on and turn-off waveforms, respectively.

As in the SEG terminals, a relatively high peak is generated at each ofthe frame switching timings X and Y. Further, disconnection and shortcircuit in the circuit wiring connected to the n-th COM terminal can bedetected based on the frame time L and the number of the terminals.

Fir example, in the sensor output as shown in FIG. 5(a), a differentialwaveform is detected at the 4th position in the divided times. That is,it can be determined that the circuit wiring connected to the 4thterminal includes a disconnection, and thereby no voltage change iscaused at the corresponding position of the sensor. Further, thewaveform of a short circuit is the same as that in the SEG terminals.That is, if one circuit wiring in the circuit-wiring group includes ashort circuit, voltage in the booster circuit is varied by driving theterminal connected to this circuit wiring, and then voltage changes arecaused in all of the terminals. This leads to a significant disorder inthe sensor output waveform. FIG. 5(b) shows that the two circuit wiringsconnected to the N-1-th and N-2-th terminals are short-circuitedmutually.

With reference to the flowchart of FIG. 6, the processing flow in theinspection operation will be described below.

In Step S-610, each position of frame inversions on a time axis is firstdetected. This can be achieved by detecting peaks each appearsapproximately periodically and equal to or greater than a given value.In Step S-602, the period of time between the peaks of the frameinversions is then measured to determine a frame time.

In Step S-603, L/N is derived from dividing the frame time L by thenumber of the terminals N. After initializing the terminal number n inStep S-604, n is incremented in Step S-605, and n L/N is calculated tospecify a range on the time axis in which the voltage of the circuitwiring connected to the n-th terminals is to be detected. By comparingthe sensor output waveform falling within in the range to a normalsensor output waveform or comparing a threshold derived from the normalsensor output waveform to a peak of the actual output, it is detectedwhether voltage change is caused in the n-th circuit wiring. Morespecifically, in the inspection operation of the SEG circuit-wiringgroup, when the peak of the actual output is equal to or less than acertain threshold, it is determined that the circuit wiring includes adisconnection. Further, when the peak of the actual output is equal toor less than another threshold, it is determined that the circuit wiringincludes a short circuit. In the inspection operation of the COMcircuit-wiring group, when the peak of the actual output is equal to orgreater than a certain threshold, it is determined that the circuitwiring includes a disconnection. Further, when the peak of the actualoutput is equal to or greater than another threshold greater than thecertain threshold, it is determined that the circuit wiring include ashort circuit.

If one of disconnection and short circuit is determined in Step S-606,the process proceeds from Step S-607 to Step S-608, and the circuitwiring number n and its determined defect are recorded. In Step S-609, nis then compared to N in order to determine if the inspection operationfor the entire circuit-wiring groups is completed. If n is less than N,the process returns to Step S-605. After n is incremented, theprocessing in Step S-606 to Step S-608 will be repeated. When n is equalto N, the completion of the inspection operation for the entirecircuit-wiring groups is determined, and the processing is terminated.

When it is required to remove a defective circuit board even if only onedefect is included in circuit wirings of the circuit board, in responseto YES in Step S-607, the defect of the circuit board is notified to auser, and then the processing of this circuit board may be terminatedwithout completing the inspection operation for the entirecircuit-wiring groups. Otherwise, without the storing process in StepS-608, the defect of the circuit board may be simply notified to a user.

As above, in the inspection system according to this embodiment,disconnection and/or short circuit in the circuit board having theonboard LCD driving LSI as an integrated circuit are detected in anon-contact manner. Thus, even if highly fine circuit patterns areintroduced in the market, it is unnecessary to prepare mechanisms andspend much time for troublesome positioning operations. Further, the jigis not damaged and desired automatic mechanization can be facilitatedbecause any probe is not used in the inspection system.

In addition, the inspection system according to this embodiment caninspect a circuit board having an onboard LSI. In the same state, theLSI itself can also be inspected (an inspection of current consumptionduring operation, an inspection and measurement of voltage, aninspection of frame frequency or the like), and thereby the time forinspecting the entire LSD driver module can be remarkably reduced.

While the inspection system according to this embodiment detects voltagechanges in the circuit wirings, the quantity and radiative configurationof an electromagnetic wave emitted from the circuit board may bedetected. When the electromagnetic wave has a given quantity andconfiguration, it is determined that the circuit wiring has a normalcontinuity. If the electromagnetic wave has a quantity less than a givevalue and a configuration different from a given criterion, it isdetermined that the circuit wiring has a defect.

EXAMPLE

For the purpose of reference, actual sensor output waveforms are shownin FIGS. 7 and 8. FIGS. 7 and 8 show detect waveforms on the side of theSEG and COM terminals, respectively.

These data was measured by driving a work having a number 80 of COMterminals and a number 128 of SEG terminals and sampling waveforms usingframe outputs as triggers. In particular, the SEG terminals weresequentially driven in units of 32 terminals to generate output signalswith skipping two terminals so as to determine the outputs of the SEGterminals independently.

As a result, in case of a total number 250 of the SEG and COM terminals,a single work could be inspected within 1.5 to 3 seconds, and four worksarranged in parallel with each other could be inspected within 3 to 7seconds.

INDUSTRIAL APPLICABILITY

The present invention can provide an apparatus and method for inspectinga circuit board at a high speed.

1. An apparatus for inspecting a circuit board incorporating anintegrated circuit, comprising: drive means for forcibly driving saidintegrated circuit to generate output signals sequentially from aplurality of output terminals of said integrated circuit; detect meansfor detecting in a non-contact manner a voltage change in a plurality ofcircuit wirings connected to said output terminals; comparison means forcomparing the magnitude of the detected voltage change to a given value;and defect determination means for determining a defect in said circuitwirings according to the comparison result in said comparison means. 2.An apparatus as defined in claim 1, wherein said output signals arepulse waves.
 3. An apparatus as defined in claim 2, wherein said detectmeans is adapted to generate a waveform representing the voltage change,and wherein when said waveform includes an abnormal waveform, saiddefect determination means is operable to identify defective one or onesof said plurality of circuit wirings according to the location of saidabnormal waveform on a time axis.
 4. An apparatus as defined in claim 2,wherein said detect means includes a sensor board opposed to saidplurality of circuit wirings in a non-contact manner to detect thevoltage change in any one part of said plurality of circuit wiring. 5.An apparatus as defined in claim 4, wherein said sensor board includes asingle metal plate having a dimension arranged to cover said pluralityof circuit wirings, said metal plate including a single output terminal.6. An apparatus as defined in claim 2, wherein said plurality of circuitwirings are driven to sequentially generate pulse signals as said outputsignals, and wherein said detect means is operable to sequentiallydifferentiate the pulse signals and add the differential values topresent the sum as a single output waveform representing the voltagechange.
 7. An apparatus as defined in claim 2, wherein responsive to thecomparison result in said comparison means indicating that the magnitudeof the voltage change is equal to or less than said given value, saiddetermination means is operable to determine that the circuit wiringcorresponding to said voltage change includes a disconnection.
 8. Anapparatus for inspecting a circuit board for use in an LCD driver,comprising: detect means for detecting in a non-contact manner a voltagechange in all of circuit wirings connected in a one-on-one arrangementto terminals of an LSI for use in an LCD driver; determination means fordetermining whether or not the magnitude of the detected voltage changeis normal or abnormal; and identification means responsive to thedetermination of an abnormality in the voltage change to identifydefective one or ones of said circuit wirings according to the timing ofoccurrence of said abnormal voltage change.
 9. An apparatus as definedin claim 8, wherein said voltage change is detected as a pulse wave. 10.An apparatus as defined in claim 9, which further includes drive meansfor forcibly driving said LSI to generate output signals sequentiallyfrom said terminals of said LSI.
 11. An apparatus as defined in claim 9,wherein said terminals are segment terminals, and wherein saiddetermination means is operable responsive to the voltage change lessthan a given value to determine that the circuit wiring corresponding tosaid voltage change includes a disconnection.
 12. An apparatus asdefined in claim 9, wherein said terminals are common terminals, andwherein said determination means is operable responsive to the voltagechange greater than a given value to determine that the circuit wiringcorresponding to said voltage change includes a disconnection.
 13. Anapparatus as defined in claim 9, wherein said determination means isoperable responsive to the voltage change greater than a given value todetermine that the circuit wiring corresponding to said voltage changeincludes a short-circuit.
 14. An apparatus as defined in claim 9,wherein said timing of the occurrence of said abnormal voltage change isdefined by a location on a time axis between adjacent timings of frameinversion detected as periodical major voltage changes in said detectmeans.
 15. A method for inspecting a circuit board incorporating anintegrated circuit, comprising the steps of: forcibly driving saidintegrated circuit to generate output signals sequentially from aplurality of output terminals of said integrated circuit; detecting in anon-contact manner a voltage change in a plurality of circuit wiringsconnected to said output terminal; comparing the magnitude of thedetected voltage change to a given value; and determining a defect insaid circuit wirings according to the comparison result in saidcomparing step.
 16. An apparatus as defined in claim 15, wherein saidoutput signals are pulse waves.
 17. A method as defined in claim 16,wherein said detecting step includes the step of generating a waveformrepresenting the voltage change, and wherein said defect determinationstep includes the step of when said waveform includes an abnormalwaveform, identifying defective one or ones of said plurality of circuitwirings according to the location of said abnormal waveform on a timeaxis.
 18. A method as defined in claim 16, wherein said detection stepincludes the step of positioning a sensor board opposedly to saidplurality of circuit wirings in a non-contact manner to detect thevoltage change in any one part of said plurality of circuit wiring. 19.A method as defined in claim 18, wherein said sensor board includes asingle metal plate having a dimension arranged to cover said pluralityof circuit wirings, said metal plate including a single output terminal.20. A method as defined in claim 16, wherein said driving step includesthe step of forcibly driving said plurality of circuit wirings tosequentially generate pulse signals as said output signals, and whereinsaid detecting step includes the step of sequentially differentiate thepulse signals and add the differential values to present the sum as asingle output waveform representing the voltage change.
 21. A method asdefined in claim 16, wherein said determining step includes the step ofresponsive to the comparison result in said comparing step indicatingthat the magnitude of the voltage change is equal to or less than saidgiven value, determining that the circuit wiring corresponding to saidvoltage change includes a disconnection.
 22. A method for inspecting acircuit board for use in an LCD driver, comprising the steps of:incorporating in said circuit board an LSI for use in an LCD driver;forcibly driving said LSI to generate output signals sequentially fromall of circuit wirings connected in a one-on-one arrangement toterminals of said LSI; detecting a voltage change in said circuitwirings in a non-contact manner; determining whether or not themagnitude of the detected voltage change is normal; and responsive tothe determination of an abnormality in the voltage change, identifyingdefective one or ones of said circuit wirings according to the timing ofsaid determination.
 23. An apparatus as defined in claim 22, whereinsaid output signals are pulse waves.
 24. A method as defined in claim23, wherein said terminals are segment terminals, and wherein saiddetermining step includes the step of responsive to the voltage changeless than a given value, determining that the circuit wiringcorresponding to said voltage change includes a disconnection.
 25. Amethod as defined in claim 23, wherein said terminals are commonterminals, wherein said determining step includes the step of responsiveto the voltage change greater than a given value, determining that thecircuit wiring corresponding to said voltage change includes adisconnection.
 26. A method as defined in claim 23, wherein saiddetermining step includes the step of responsive to the voltage changegreater than a given value, determining that the circuit wiringcorresponding to said voltage change includes a short-circuit.
 27. Amethod as defined in claim 23, wherein said timing of occurrence of saidabnormal voltage change is defined by a location on a time axis betweenadjacent timings of frame inversion detected as periodical major voltagechanges in said detecting step.